Playing Melodically on One String (Part 2)

This lesson tackles melodic playing on one string using the pentatonic scale. I discussed the topic in passing in the "only pentatonic scale lesson you will ever need" video, but this discussion goes into more depth and suggests a few exercises to help you practice. When you master these exercises, you'll be able to move up and down the neck quickly and seamlessly, and you'll be able to easily switch back and forth between the pentatonic scale and the major scale modes on the fly.

Playing melodically on one string (part 2)

In part one, I described how to play the major scale on one string and how to use melodic patterns with position shifts to make your scale patterns sound less like scales. In this lesson, I’ll do the same for the pentatonic scale and show you how to easily shift between pentatonic scales and the modes.

Pentatonic scales on the fretboard

In many of my lessons, I describe the pentatonic scale geometrically—as being made up of two simple shapes called the rectangle and the stack. This section is a brief refresher. The following diagrams use all-fourths tuning so that we can temporarily ignore the warp between the G and B strings. If this recap is confusing, I recommend rewatching the video.

Of course, on a real fretboard, we must adapt these patterns to the major 3rd interval between the G and B strings. We can visualize an imaginary line between the G and B strings. Any geometric shape (e.g., a rectangle or stack) that falls across this line will be warped in a predictable way. If two shapes fall on opposite sides of the line, their vertical alignment will be offset by one fret.

In the next section, it will be helpful to be able to refer to the individual strings of the rectangle and stack by unique labels, so we’ll adopt a simple naming convention. In the rectangle, we will label the strings U and L for upper and lower. The stack’s three strings will be labeled T, M, and B for top, middle, and bottom. This gives us five unique labels for the five intervals in a pentatonic scale.

The minor pentatonic scale on one string

Pentatonic scales consist of 2-fret and 3-fret distances, which are major second and minor third intervals, respectively.

There are two minor third intervals: R-♭3 and 5-♭7. Two adjacent major seconds connect ♭3-4 and4-5, and one more connects ♭7-R.

It is helpful to visualize how rectangles and stacks relate to these intervals. As you play up and down one string, try to maintain awareness of where the neighboring rectangles and stacks are. This makes it easy to switch from playing horizontally to vertically (and vice versa) at any time.

It’s worth remembering a few key relationships in this pattern. Whenever you see two adjacent whole steps, the lower one is the top of a stack (T), and the higher one is the bottom of another stack (B). If you see a whole step surrounded by minor thirds, it’s the middle of a stack (M), with L toward the nut and U toward the bridge. Each of these can be a jumping-off point for switching to vertical playing.

Exercise 1: Choose a key, and practice playing the minor pentatonic scale along one string. Start at a root and play upward until you reach the highest accessible fret. Then, play downward until you reach the nut. At all times, keep track of which rectangle or stack your fingers are on.

Exercise 2: Like Exercise 1, play the minor pentatonic scale on one string, but practice using larger intervals. Try playing the scale “in fourths” by skipping a note and then back-tracking to the note you skipped. An example ascending sequence is R-4-♭3-5-4-♭7-5-R. Descending would be R-5-♭7-4-5-♭3-4-R.

Exercise 3: Starting on the open high E string, play the E minor pentatonic scale up the string until you run out of frets. Then, switch to the B string by using the rectangle and stack relationships and play the same scale descending along the B string until you reach the nut. Continue to the lower strings, alternating ascending and descending scales. When you get to the low E string, reverse directions and continue alternating until you get back to the high E string.

Exercise 4: Mix up multiple movement modalities. Play along one string for a while, then shift to playing vertically within a pattern. Then, switch back to playing horizontally along a different string. Move around until you come to a stack, and then play diagonally across multiple stacks. Rinse and repeat until you feel comfortable moving all over the fretboard. For an added challenge, whenever you reach a root, give it an accent or play it twice for emphasis.

The major pentatonic scale on one string

The major pentatonic scale contains the same sequence of intervals as the minor pentatonic, except it starts with the pair of major second intervals.

The relationships with the rectangles and stacks are also identical—just shifted over by one interval. In other words, the major pentatonic scale is what you would get by starting the minor pentatonic scale on the ♭3rd, and the minor pentatonic scale is equivalent to starting the major pentatonic scale on the 6th.

Exercise 5: Repeat exercises 1-4 with the major pentatonic scale, emphasizing the root each time you play it.

Shifting to a mode

To shift to a mode, we will use the “hidden in plain sight” methodology to add in the two color notes of each mode. Recall that there are three minor and three major modes. From darkest to brightest, the minor modes are Phrygian, Aeolian, and Dorian, and the major modes are Mixolydian, Ionian, and Lydian. The two missing notes needed to convert a pentatonic scale into a mode are arranged in predictable ways relative to the rectangle and stack. For full details, see the “Hidden in Plain Sight” video.

When playing on one string, you will only need to focus on the rectangle, and this is easy for the Dorian, Lydian, Phrygian, and Mixolydian modes, because in each scale, the added notes on the upper and lower strings of the rectangle are in the same relative position—both shifted toward the bridge (Dorian/Lydian) or toward the nut (Phrygian/Mixolydian).

We need to be a little more careful with the Ionian and Aeolian modes because we must remember which minor third interval corresponds to the upper string of the rectangle and which is the lower.

Exercise 6: Choose a mode and key (e.g., A Dorian). On one string, find the root and play the appropriate pentatonic scale up and down that string. Focus on visualizing the intervals of the pentatonic scale and add in the color notes of the mode by filling in the minor thirds with the added notes from the rectangle.

Once you have identified where you are within a mode, you can choose to switch to visualizing the underlying major scale pattern and then use the methods from Part 1 of this lesson to continue navigating up and down the string. Or you can continue visualizing the pentatonic scale and add in the modal color notes on the fly as we have just done.

Shifting back to pentatonic

Once you have switched to visualizing the underlying major scale, switching back to the pentatonic scale can be a bit tricky.

One method is to pivot from the root of the mode to the root of the parallel pentatonic scale. Since each mode corresponds to a particular scale degree of the underlying major scale (Dorian = 2, Phrygian = 3, etc.), simply locate that scale degree within the major scale pattern and shift to thinking of that note as the root of the parallel major or minor pentatonic scale.

A more general method is to find a root by name on any string in the vicinity of your fingers, visualize the appropriate rectangle or stack there, and then use your knowledge of how rectangles and stacks map to the horizontal pentatonic scale to jump back into the pentatonic world.

Exercise 7: Building on Exercise 6, practice pivoting from visualizing the pentatonic scale to visualizing the underlying major scale pattern. When you are ready to switch back to pentatonic, use one of the above-mentioned root-finding methods.